Anathematic Secrecy. The hulk can't be targeted by any divination magic or perceived through magical scrying sensors.
Aura of Mind Erosion. Any hostile creature that starts its turn within 30 feet of the hulk must make a DC 15 Intelligence saving throw. On a failed save, a creature suffers disadvantage on all Wisdom and Charisma saving throws until the start of the hulk's next turn.
Innate Spellcasting. The hulk's innate spellcasting ability is Constitution (spell save DC 15). She can innately cast the following spells, requiring no components:
At will: conjure minor elementals, enemies abound
3/day each: dispel magic, fear, levitate
2/day each: phantasmal force, phantasmal killer
1/day each: dominate monster, mental prison
Magic Resistance. The hulk has advantage on saving throws against spells and other magical effects.
Magic Weapons. The hulk's weapon attacks are magical.
Unyielding Essence. The hulk is immune to any spell or effect that would alter her form, as well as those that would read her thoughts, determine if she is lying, or magically influence her thoughts or behavior.
Multiattack. The hulk makes two slam attacks.
Slam. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 16 (2d10 + 5) bludgeoning damage plus 7 (2d6) psychic damage.
Breath Weapon (Recharge 5-6). The hulk exhales elemental energy in a 15-foot cone. Each creature in that area must make a DC 15 Constitution saving throw, taking 24 (7d6) damage on a failed save, or half as much damage on a successful one. The breath deals acid, cold, fire, or lightning damage (hulk's choice).